U.S. patent number 8,322,482 [Application Number 12/891,128] was granted by the patent office on 2012-12-04 for tractor ground positioning system.
This patent grant is currently assigned to Deere & Company. Invention is credited to Mark D. Evans, William O. Ifode, David L. Sprinkle.
United States Patent |
8,322,482 |
Sprinkle , et al. |
December 4, 2012 |
Tractor ground positioning system
Abstract
A tractor ground positioning system includes ground positioning
controls outside of an operator station of the tractor that can be
actuated by an operator while maintaining contact with the tractor
to move the tractor forward or reverse to connect an implement. A
controller commands the tractor to move at a desired ground speed
only while the operator continues actuating the controls.
Inventors: |
Sprinkle; David L. (Warrenton,
GA), Ifode; William O. (Grovetown, GA), Evans; Mark
D. (Grovetown, GA) |
Assignee: |
Deere & Company (Moline,
IL)
|
Family
ID: |
44674546 |
Appl.
No.: |
12/891,128 |
Filed: |
September 27, 2010 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20120073894 A1 |
Mar 29, 2012 |
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Current U.S.
Class: |
180/321; 701/50;
180/53.2; 180/336 |
Current CPC
Class: |
A01B
63/118 (20130101); B60D 1/62 (20130101); B60D
1/36 (20130101) |
Current International
Class: |
B60K
23/00 (20060101) |
Field of
Search: |
;180/53.2,53.3,320,321,336 ;701/50 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Dickson; Paul N
Assistant Examiner: Wilhelm; Timothy
Claims
The invention claimed is:
1. A tractor ground positioning system comprising ground
positioning controls on the tractor outside an operator station of
the tractor and adjacent a three point hitch on the tractor; the
ground positioning controls actuated only by direct and continuous
contact; a seat switch in the operator station indicating if there
is a seated operator; and a controller electrically connected to
the ground positioning controls to command a transmission of the
tractor to move the tractor at a desired ground speed in forward or
reverse over short distances if the seat switch indicates the
absence of a seated operator and while the controls remain
continuously actuated.
2. The tractor ground positioning system of claim 1 wherein the
ground positioning controls includes a forward switch and a reverse
switch on the tractor.
3. The tractor ground positioning system of claim 2 wherein the
ground positioning controls include an engagement switch adjacent
the forward switch and reverse switch.
4. The tractor ground positioning system of claim 1 further
comprising an enable switch in the operator station of the tractor
that must be actuated before actuating the ground positioning
controls.
5. The tractor ground positioning system of claim 1 further
comprising at least one system check that must be satisfied before
actuating the ground positioning controls.
6. The tractor ground positioning system of claim 1 further
comprising a first speed sensor connected to the controller and
sensing the actual ground speed of the tractor.
7. The tractor ground positioning system of claim 6 wherein the
controller includes a control algorithm to adjust the ground speed
of the tractor if the actual ground speed received from the first
speed sensor does not match the desired slow ground speed.
8. A tractor ground positioning system comprising: ground
positioning controls on the tractor outside an operator station of
the tractor and adjacent a three point hitch on the tractor; the
ground positioning controls actuated only by direct and continuous
contact; a controller electrically connected to the ground
positioning controls to command a transmission of the tractor to
move the tractor at a desired ground speed in forward or reverse
over short distances while the controls remain continuously
actuated; a first speed sensor connected to the controller and
sensing the actual ground speed of the tractor; and, a second speed
sensor connected to the controller and sensing the actual ground
speed of the tractor.
9. A tractor ground positioning system comprising: a forward ground
positioning control and a reverse ground positioning control
outside an operator station of the tractor that can be actuated
only from the ground while in contact with the tractor adjacent a
hitch on the tractor; a transmission having a plurality of
different operator selectable ranges including a low range; a
controller that commands the tractor to move at a desired ground
speed only if a low range of the transmission is selected and while
continuously actuating either of the ground positioning controls;
and a speed sensor connected to the controller causing the
controller to discontinue commanding the tractor to move at the
desired ground speed if the actual ground speed sensed by the speed
sensor does not match the desired ground speed.
10. The tractor ground positioning system of claim 9 further
comprising an enable switch in the operator station that must be
actuated before actuating either of the ground positioning controls
outside the operator station.
11. The tractor ground positioning system of claim 9 further
comprising an engagement switch adjacent the forward ground
positioning control and the reverse ground positioning control that
must be actuated while the forward ground positioning control or
the reverse ground positioning control are actuated.
12. The tractor ground positioning system of claim 9 wherein the
controller further comprising a control algorithm to adjust the
ground speed of the tractor to match the desired ground speed.
13. A tractor ground positioning system comprising: an enable
switch, a foot pedal and a park brake in a tractor operator
station; a ground positioning control switch adjacent a three point
hitch on the tractor that may be actuated only from outside the
tractor operator station; a controller connected to the enable
switch, foot pedal, park brake and ground positioning control
switch, that commands the tractor to move at a desired ground speed
only if the enable switch, park brake and ground positioning
control switch are actuated, and the foot pedal is not
actuated.
14. The tractor ground positioning system of claim 13 further
comprising a plurality of system checks that the controller must
determine are satisfied before commanding the tractor to move at
the desired ground speed.
15. A tractor ground positioning system comprising: an enable
switch in a tractor operator station; a ground positioning control
switch adjacent a three point hitch on the tractor that may be
actuated only from outside the tractor operator station; a
controller connected to the enable switch and ground positioning
control switch that commands the tractor to move at a desired
ground speed only if the enable switch and ground positioning
control switch are actuated; a plurality of system checks that the
controller must determine are satisfied before commanding the
tractor to move at the desired ground speed; wherein one of the
system checks is a seat switch in the operator station to detect
the absence of a seated operator.
16. The tractor ground positioning system of claim 15 further
comprising a ground speed sensor connected to the controller to
sense the actual ground speed of the tractor.
17. The tractor ground positioning system of claim 16 wherein the
controller adjusts the command to move the tractor at the desired
ground speed based on information from the ground speed sensor.
18. A tractor ground positioning system comprising: an enable
switch in a tractor operator station; a ground positioning control
switch adjacent a three point hitch on the tractor that may be
actuated only from outside the tractor operator station; a
controller connected to the enable switch and ground positioning
control switch that commands the tractor to move at a desired
ground speed only if the enable switch and ground positioning
control switch are actuated; wherein a park brake must be engaged
to move the tractor at the desired ground speed.
Description
FIELD OF THE INVENTION
This invention relates generally to ground positioning system for a
tractor or other work vehicle for use in connecting the tractor or
vehicle with an implement or trailing attachment.
BACKGROUND OF THE INVENTION
Three point hitches designed in accordance with ISO 730 have been
used for many years and are universally accepted for attaching
implements or trailing attachments to tractors or other work
vehicles. The ISO 730 hitch requires precise alignment of the
tractor to the implement so that the implement may be attached
easily, usually by backing up the tractor. However, it may be
difficult to precisely align the tractor to the implement. As a
result, attaching the implement often requires two persons.
Three point hitches may be raised and lowered using switches remote
from the operator station of the tractor. For example, electrical
or electro-hydraulic controls for a three point hitch may be
located adjacent the rear of the tractor, typically on the
tractor's right or left rear fenders. These control devices make it
more convenient for the operator to hook up rear mounted implements
while off the tractor.
For example, a pair of switches may be located adjacent the rear of
the tractor, one switch to supply a signal to a valve or valves to
raise the hitch, and the other switch to supply a signal to lower
the hitch. Even with the controls mounted on the fender, however,
changing rear mounted implements on a three point hitch can be
labor intensive because of the difficulty and time required to
accurately position the tractor with respect to the implement.
Quick attaching couplers also have been developed to allow faster
attachment of three point hitches to rear mounted implements from
the operator station of the tractor. A quick attaching coupler may
be an inverted U-shape arch that is attached to the conventional
three points of a tractor hitch. The frame of a quick attaching
coupler may have an upper hook with a long, tapered point and two
lower coupling hooks or jaws with a latching and unlatching
arrangement to hold the implement hitch pins. To hook up a quick
attaching coupler to an implement, the hitch may be lowered and the
tractor backed into place near the implement. Then the hitch may be
raised with the hydraulic system so that the upper hook engages the
upper pin on the implement. Further lifting causes the weight of
the implement to force the lower hitch pins to enter the lower
hooks.
Quick attach and auto hitch systems have not eliminated the
inherent difficulty in attaching some implements. For example, an
operator may need to back up the tractor several times to get in
exactly the right position for the implement. After each attempt,
the operator may need to dismount from the tractor operator station
and try completing the attachment process. Additionally, quick
attaching couplers may not be useful or suitable for many older
attachments, nonstandard attachments, and attachments that do not
sit level on the ground surface when detached. It may be difficult
for an operator to complete attachment of some implements because
it may require repositioning the tractor.
For these reasons, there is a need for greater operator safety and
ease of use when hooking up a tractor to implements and other
trailing attachments. A system is needed to make changing rear
mounted implements easier for the operator. A system is needed to
reduce the repeated back up positioning of the tractor to the
implement, and to help accurately position the tractor. A system is
needed that lets an operator complete the attachment process
without repeatedly dismounting from the tractor.
SUMMARY OF THE INVENTION
A tractor ground positioning system includes controls on the outer
surface of the tractor outside the operator station, to move the
tractor slowly in forward or reverse for short distances. The
controls may be within reach of an operator who is on the ground
while connecting an implement to the tractor, preferably on a
fender or other outer surface. While on the ground, the operator
may actuate one or more ground positioning controls to move the
tractor into position for a short distance. The operator must
continuously actuate the ground positioning controls while
remaining in direct contact with the controls on the tractor. If
the operator discontinues contact with the controls on the tractor,
the ground positioning system will cause the tractor to stop
moving.
The ground positioning system provides greater operator safety and
ease of use when hooking up a tractor to rear mounted implements.
The tractor ground positioning system makes changing rear mounted
implements easier for the operator. The system reduces the repeated
back up positioning of the tractor to the implement, and helps
accurately position the tractor. The system lets an operator
complete the attachment process without repeatedly dismounting from
the tractor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear view of a tractor with a ground positioning system
according to one embodiment of the invention.
FIG. 2 is a rear view of controls for a tractor ground positioning
system according to one embodiment of the invention.
FIG. 3 is a block diagram of a tractor ground positioning system
according to one embodiment of the invention.
FIG. 4 is a logic diagram of a tractor ground positioning system
according to one embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In one embodiment shown in FIGS. 1 and 2, tractor ground
positioning system 10 may include ground positioning controls 11
with forward switch 15 and reverse switch 16 located on the outer
surface of the tractor outside the operator station. For example,
the ground positioning controls may be located at the rear of the
tractor, preferably on a fender or other outer surface within reach
of an operator who is standing on the ground while he or she also
can reach the tractor's three point hitch 18. While on the ground,
the operator may actuate the ground positioning controls to move
the tractor slowly over short distances into position for
connecting an implement to the tractor.
The ground positioning controls are mounted on a location on the
tractor where implement attachment is done. The controls allow the
operator to move the vehicle while he or she is in close proximity
to the task being performed.
In one embodiment, to move the tractor using the ground positioning
system, the operator must continuously actuate the ground
positioning controls which require the operator to remain in direct
contact with the controls on the tractor. The operator may actuate
these controls while standing near the rear of the tractor, after
exiting the operator station. If the operator discontinues contact
with the controls on the tractor, the ground positioning system
will cause the tractor to stop moving.
In one embodiment, ground positioning controls 11 may be any
switch, button or other momentary contact that an operator must
continuously press to remain actuated. Only one of the forward
switch and reverse switch may be actuated at a given time. For
example, the forward and reverse switches may be configured as a
toggle switch with a spring to return to a neutral position, when
neither switch is actuated.
In one embodiment, an operator may actuate either of switches 15,
16 on the tractor to move the tractor slowly forward or backward
into a position where he or she can connect an implement to the
three point hitch of the tractor. The ground positioning system is
supplemental to the operator station controls, and may be used for
moving the tractor for short distances, typically less than about
0.5 meters. Although the ground positioning controls in a preferred
embodiment are located at the rear of the tractor, the controls
also may be mounted at the front of the tractor for the purpose of
moving the tractor a short distance in position to connect an
implement to a front three point hitch.
In one embodiment, the ground speed of the tractor when operating
the ground positioning system may be fixed at a desired speed of
below about 25 mm per second and preferably about 10 mm per second.
For example, the ground positioning system may specify and set the
ground speed of the tractor below any speed normally attainable by
the operator using the pedals in the operator station.
Alternatively, the ground speed with the ground positioning system
may be variable from zero up to a preset maximum safe speed for
ground positioning while the operator is off the tractor. The
maximum allowable speed may be independent of engine speed, or of
range transmission gear selection.
In one embodiment, the ground speed of the tractor may be sensed by
one or more Hall effect sensors which provide feedback signals to
controller 20 so that the selected speed is maintained regardless
of the range transmission gear selection or engine speed. For
example, the desired ground speed may be variable between a minimum
speed of zero and a maximum of not more than about 25 mm per
second.
In one embodiment, forward and reverse switches 15, 16 may be moved
by the operator to actuate a potentiometer that is signal connected
to controller 20. The controller may be programmed to send a
proportional speed signal, in response to, and proportional to, a
signal from the potentiometer, to the respective solenoid 31, 34,
depending on which switch is actuated. The proportional speed
signal may range from a zero speed signal up to the pre-programmed
maximum speed signal corresponding to the maximum travel or
position of the forward and reverse switches.
Alternatively, in one embodiment of the invention, ground
positioning controls 11 also may include engagement switch 14 which
the operator must engage at the same time as the forward or reverse
switch while he or she is out of the operator station. The
proportional speed signal may range from a zero speed signal up to
the pre-programmed maximum speed signal corresponding to the
maximum travel or position of the engagement switch.
In one embodiment, the ground positioning system may include one or
more speed sensors. For example, first rotation speed sensor 44,
such as a Hall effect sensor, may be arranged adjacent a rotating
part of range transmission, such as gear 46 that rotates in direct
proportion to the vehicle ground speed. Controller 20 may receive a
frequency signal from sensor 44 indicating the actual speed, and
compare it to the desired speed. If the actual speed is not the
same as the desired speed, the controller then may adjust the
output speed signal to the proportional pressure reducing valve
solenoids 30, 34 using a PID control algorithm to reach the desired
speed. Alternatively, other control algorithms may be used to reach
or approach the desired speed.
Optionally, second rotation speed sensor 48 may be arranged
adjacent another rotating part of the range transmission, such as
gear 49 that also may rotate in direct proportion to the vehicle
ground speed. The second rotation speed sensor may be used to
verify that the actual ground speed is not different from the
desired speed. For example, if the second rotation speed sensor
indicates a difference, the controller may provide a command to
engine controller or ignition module 55 to discontinue operation of
the tractor ground positioning system or stop the engine.
Alternatively, ground speed detection and feedback may be
accomplished by a hydrostatic pump displacement control system.
This control system may control the angle of the swash plate of the
hydrostatic pump using an angle sensor, which may be indicative of
the tractor ground speed.
Additionally, in one embodiment, tractor ground positioning system
10 may be enabled by enable switch 17 located in the operator
station of the tractor. Controller 20 may include logic requiring
the operator to actuate the enable switch in the operator station
before actuating any of the ground positioning controls at the rear
of the tractor. Additionally, while the operator is actuating the
ground positioning controls at the rear of the tractor, the system
may disable the controls in the operator station including the
forward and reverse pedals. After the operator discontinues
actuating the ground positioning controls, the controls in the
operator station then may be used. The operator station controls
may disable the ground positioning controls.
In one embodiment shown in FIG. 3, tractor ground positioning
system 10 may be used with a tractor having an engine 51 which
rotationally drives hydrostatic transmission 52. The hydrostatic
transmission may include variable displacement hydrostatic pump 60
and hydraulic motor 62. The hydrostatic transmission may drive a
multi-speed gear transmission 54, for transmitting power to one or
more drive wheels 56. The tractor speed may be controlled by
adjustment of the speed output of the hydrostatic transmission.
In one embodiment, for normal operation of the tractor from the
operator station, the operator may use forward pedal 22 and reverse
pedal 24. The forward pedal may be operatively engaged with
potentiometer 26 to produce a forward pedal position signal, and
the reverse pedal may be operatively engaged with potentiometer 28
to produce a reverse pedal position signal. The potentiometers may
be signal-connected to electronic controller 20.
In one embodiment, electronic controller 20, such as a
microprocessor-based microcontroller, may be signal-connected,
through signal conditioning or amplifying circuitry, to solenoid 31
of forward drive proportional pressure control valve 32 and to
solenoid 34 of reverse drive proportional pressure control valve
36. The output current to energize the forward or reverse pressure
control valves may be substantially proportional to the
corresponding position signals from the forward and reverse pedals
respectively.
In one embodiment, before operating the tractor ground positioning
system, the controller must determine that at least one or more
system checks are satisfied. For example, the system checks may be
in the form of switches or electronic signals that controller 20
may receive from other devices on the tractor. For example, the
system checks may require seat switch 64 to detect the absence of a
seated operator at the operator station of the tractor. In other
words, the ground positioning system may not be actuated to move
the tractor if an operator is seated at the operator station. The
system checks also may include park brake switch 66 to detect the
park brake is engaged. The park brake also may remain engaged while
the ground positioning system causes the tractor to move slowly in
forward or reverse. Additionally, the system checks may require
forward pedal 22 and reverse pedal 24 to be at home, and not be
actuated. The system checks may require the speed of engine 51 to
be under a specified value such as 1200 rpm. The system checks may
require transmission 54 to be in a specified low range such as the
"A" range. The system checks may require one or more speed sensors
44, 48 to be working and operational, and may require the ground
speed of the tractor to be zero. Thus, the controller may not
permit the ground positioning controls to cause the transmission or
other device to move the tractor in forward or reverse at the
desired ground speed until and unless one or more system checks are
and remain satisfied.
Alternatively, in one embodiment, ground positioning system 10 may
be used with a tractor or vehicle having one or more electric wheel
motors instead of a hydrostatic transmission. The operator may
actuate the ground positioning controls at the rear of the tractor,
causing the controller to provide speed commands to each electric
wheel motor to rotate at the desired speed. In another alternative
embodiment, the ground positioning system may be used with a
directional reversing transmission that uses electronically
controlled forward and reverse clutches, by modulating current to
the traction clutches while the transmission is in the lowest
gear.
In one embodiment, the tractor ground positioning system may
operate according to the logic diagram of FIG. 4. In block 200, the
vehicle controller may determine if the ground positioning enable
switch in the operator station of the tractor or other work vehicle
is actuated. If the ground positioning enable switch is actuated,
in block 202 the controller may determine if one or more system
checks are satisfied. If the system checks are satisfied, in block
204 the controller may determine if the ground positioning
engagement switch is actuated at the rear of the tractor. If the
ground positioning engagement switch is actuated, in block 206 the
controller may determine if either the forward or reverse switch at
the rear of the tractor is actuated. If the forward or reverse
switch is actuated, in block 208 the controller commands the
transmission to move the tractor in forward or reverse at the
desired speed. Optionally, the controller also may trigger an
audible warning and/or a short delay time before commanding the
tractor to move in forward or reverse.
In one embodiment, in block 210, the controller then may determine
if the actual ground speed of the tractor detected by a first
sensor matches the desired speed. If it does not match the desired
speed, in block 212 the controller may adjust the speed. For
example, a PID control algorithm, or other similar control
algorithm, may be used to adjust the actual speed toward the
desired speed. In block 214, the controller then may determine if
the actual ground speed detected by a second sensor matches the
desired speed. If it does not match the desired speed, the
controller may turn off in ground positioning system in block 216.
For example, the controller may command the transmission to move to
a neutral position. Alternatively, the controller may kill the
engine by various means such as shutting off fuel flow with a
solenoid, or grounding the engine ignition.
In one embodiment, during operation of the tractor ground
positioning system, the controller may monitor the status of the
ground positioning enable switch in the operator's station, one or
more system checks, the ground positioning engagement switch, and
the forward and reverse switches at the rear of the tractor. If any
of the switches is not actuated, or any of the system checks are
not satisfied, the controller may turn off ground positioning as
shown in block 216.
Having described the preferred embodiment, it will become apparent
that various modifications can be made without departing from the
scope of the invention as defined in the accompanying claims.
* * * * *